First of all, there is no need for you to "respond" to his claims AA isn't for him. The bottom line is that right now he's not interested, and arguing with him isn't going to change that. And honestly, if he could get sober by dancing around the tree naked in the back yard, you wouldn't care, right? It's the health/behavior issues that matter to you, not how he gets there. I know many people who have gotten sober without AA and stayed that way. Typically they are people who put their own massive efforts into changing their lives, inside and out. They might not do it with the formality of a 12-Step program, but they achieve something similar (which AA refers to as a "spiritual awakening," defined in AA's Big Book as "a personality change sufficient to recover from alcoholism").
In my own experience, though (two marriages to alcoholics and almost 9 years sober, myself), most people who claim AA "isn't for them" are still in denial about their disease and looking for loopholes that will allow them to keep drinking. They consider themselves superior to "those people" and terminally unique. It's generally a load of BS to consider oneself "better" or "different" from other alcoholics, but again, until a person is ready to see that and get a bit of humility, there is no point in arguing about it.
In terms of confiding in others about what's going on at home, I generally went with who I felt I needed to tell. It isn't gossip to talk about a problem with a close friend whom you can trust to keep personal information private. You have every right to share what you need to for your own well-being. If he doesn't like it, well, then he can quit doing hurtful things that require you to seek the support of others. Don't EVER put the alcoholic's "privacy" above your own well-being. As noted above, alcoholism thrives on secrecy, and keeping secrets tends to make us, as partners, sick.
Finally, in terms of navigating social activities, my best suggestion is to have some good boundaries for what you will and will not tolerate. You could decide that you will always have your own way to get home and that you will leave if he becomes drunk and embarrassing. If he embarrasses himself that's on him, not you. Or if he is simply too unreliable at all times, you could decide not to attend social gatherings with him--that you would go by yourself or not at all. Just suggestions--everyone has to decide what works best for him/herself.